Re: [PATCH] block: use rcu_work instead of call_rcu to avoid sleep in softirq

2018-11-28 Thread Paul E. McKenney
d this problem on linux 4.4, the latest kernel version > seems to have this problem as well. And it is very similar to the > previous one: > https://lkml.org/lkml/2018/7/9/391 > > Fix it by using RCU workqueue, which allows sleep. > > Signed-off-by: Yufen Yu Rev

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-22 Thread Paul E. McKenney
On Tue, May 22, 2018 at 09:38:13AM -0700, Linus Torvalds wrote: > On Tue, May 22, 2018 at 2:09 AM Roman Penyaev < > roman.peny...@profitbricks.com> wrote: > > > Should I resend current patch with more clear comments about how careful > > caller should be with a leaking pointer? > > No. Even if we

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-22 Thread Paul E. McKenney
On Tue, May 22, 2018 at 11:09:16AM +0200, Roman Penyaev wrote: > On Mon, May 21, 2018 at 5:31 PM, Paul E. McKenney > wrote: > > On Mon, May 21, 2018 at 03:50:10PM +0200, Roman Penyaev wrote: > >> On Sun, May 20, 2018 at 2:43 AM, Paul E. McKenney > >> wrote: > &

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-22 Thread Paul E. McKenney
On Tue, May 22, 2018 at 11:09:08AM +0200, Roman Penyaev wrote: > On Mon, May 21, 2018 at 5:33 PM, Paul E. McKenney > wrote: > > On Mon, May 21, 2018 at 08:16:59AM -0700, Linus Torvalds wrote: > >> On Mon, May 21, 2018 at 6:51 AM Roman Penyaev < > >> roma

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-21 Thread Paul E. McKenney
On Mon, May 21, 2018 at 08:16:59AM -0700, Linus Torvalds wrote: > On Mon, May 21, 2018 at 6:51 AM Roman Penyaev < > roman.peny...@profitbricks.com> wrote: > > > No, I continue from the pointer, which I assigned on the previous IO > > in order to send IO fairly and keep load balanced. > > Right. A

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-21 Thread Paul E. McKenney
On Mon, May 21, 2018 at 03:50:10PM +0200, Roman Penyaev wrote: > On Sun, May 20, 2018 at 2:43 AM, Paul E. McKenney > wrote: > > On Sat, May 19, 2018 at 10:20:48PM +0200, Roman Penyaev wrote: > >> On Sat, May 19, 2018 at 6:37 PM, Paul E. McKenney > >> wrote: > &

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-19 Thread Paul E. McKenney
On Sat, May 19, 2018 at 10:20:48PM +0200, Roman Penyaev wrote: > On Sat, May 19, 2018 at 6:37 PM, Paul E. McKenney > wrote: > > On Fri, May 18, 2018 at 03:03:48PM +0200, Roman Pen wrote: > >> Function is going to be used in transport over RDMA module > >> in subseque

Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

2018-05-19 Thread Paul E. McKenney
observed as empty. > > Signed-off-by: Roman Pen > Cc: Paul E. McKenney > Cc: linux-ker...@vger.kernel.org > --- > include/linux/rculist.h | 19 +++ > 1 file changed, 19 insertions(+) > > diff --git a/include/linux/rculist.h b/include/linux/rculist.h > index 1

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-08-20 Thread Paul E. McKenney
On Sun, Aug 20, 2017 at 01:31:01PM -0600, Jeffrey Hugo wrote: > On 6/29/2017 6:18 PM, Paul E. McKenney wrote: > >On Thu, Jun 29, 2017 at 10:29:12AM -0600, Jeffrey Hugo wrote: > >>On 6/27/2017 6:11 PM, Paul E. McKenney wrote: > >>>On Tue, Jun 27, 2017 at 04:32:

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-06-29 Thread Paul E. McKenney
On Thu, Jun 29, 2017 at 10:29:12AM -0600, Jeffrey Hugo wrote: > On 6/27/2017 6:11 PM, Paul E. McKenney wrote: > >On Tue, Jun 27, 2017 at 04:32:09PM -0600, Jeffrey Hugo wrote: > >>On 6/22/2017 9:34 PM, Paul E. McKenney wrote: > >>>On Wed, Jun 21, 2017 at 09:18:53AM

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-06-27 Thread Paul E. McKenney
On Tue, Jun 27, 2017 at 04:32:09PM -0600, Jeffrey Hugo wrote: > On 6/22/2017 9:34 PM, Paul E. McKenney wrote: > >On Wed, Jun 21, 2017 at 09:18:53AM -0700, Paul E. McKenney wrote: > >>No worries, and I am very much looking forward to seeing the results of > >>your tes

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-06-22 Thread Paul E. McKenney
On Wed, Jun 21, 2017 at 09:18:53AM -0700, Paul E. McKenney wrote: > On Wed, Jun 21, 2017 at 08:39:45AM -0600, Jeffrey Hugo wrote: > > On 6/20/2017 5:46 PM, Paul E. McKenney wrote: > > >On Mon, Mar 27, 2017 at 11:17:11AM -0700, Paul E. McKenney wrote: > > >>On Mon, Ma

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-06-21 Thread Paul E. McKenney
On Wed, Jun 21, 2017 at 08:39:45AM -0600, Jeffrey Hugo wrote: > On 6/20/2017 5:46 PM, Paul E. McKenney wrote: > >On Mon, Mar 27, 2017 at 11:17:11AM -0700, Paul E. McKenney wrote: > >>On Mon, Mar 27, 2017 at 12:02:27PM -0600, Jeffrey Hugo wrote: > >>>Hi Paul. > &g

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-06-20 Thread Paul E. McKenney
On Mon, Mar 27, 2017 at 11:17:11AM -0700, Paul E. McKenney wrote: > On Mon, Mar 27, 2017 at 12:02:27PM -0600, Jeffrey Hugo wrote: > > Hi Paul. > > > > Thanks for the quick reply. > > > > On 3/26/2017 5:28 PM, Paul E. McKenney wrote: > > >On Sun, Mar

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-03-27 Thread Paul E. McKenney
On Mon, Mar 27, 2017 at 12:02:27PM -0600, Jeffrey Hugo wrote: > Hi Paul. > > Thanks for the quick reply. > > On 3/26/2017 5:28 PM, Paul E. McKenney wrote: > >On Sun, Mar 26, 2017 at 05:10:40PM -0600, Jeffrey Hugo wrote: > > >>It is a race between this

Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline

2017-03-26 Thread Paul E. McKenney
On Sun, Mar 26, 2017 at 05:10:40PM -0600, Jeffrey Hugo wrote: > Hello, > > I observe that running stress-ng with the cpu-online and fstat tests > results in a deadlock of hung tasks: > > [ 366.810486] INFO: task stress-ng-cpu-o:2590 blocked for more than > 120 seconds. > [ 366.817689] Not